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470 lines
17 KiB
Mathematica
470 lines
17 KiB
Mathematica
%-----------------------------------------------------------------------------%
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% Copyright (C) 1994-2003 The University of Melbourne.
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% This file may only be copied under the terms of the GNU General
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% Public License - see the file COPYING in the Mercury distribution.
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%-----------------------------------------------------------------------------%
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% Original author: conway.
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% Extensive modification by zs.
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% Allocates the storage location for each live variable at the end of
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% each branched structure, so that the code generator will generate code
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% which puts the variable in the same place in each branch.
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% This module requires arg_infos and livenesses to have already been computed,
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% and stack slots allocated.
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% If the appropriate option is set, the code calls the follow_vars module
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% to help guide its decisions.
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% See compiler/notes/allocation.html for a description of the framework that
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% this pass operates within.
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%-----------------------------------------------------------------------------%
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:- module ll_backend__store_alloc.
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:- interface.
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:- import_module hlds__hlds_module.
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:- import_module hlds__hlds_pred.
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:- type store_map_run_type
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---> final_allocation
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; for_stack_opt.
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:- pred allocate_store_maps(store_map_run_type::in, proc_info::in, pred_id::in,
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module_info::in, proc_info::out) is det.
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%-----------------------------------------------------------------------------%
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%-----------------------------------------------------------------------------%
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:- implementation.
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:- import_module check_hlds__mode_util.
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:- import_module hlds__goal_util.
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:- import_module hlds__hlds_goal.
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:- import_module hlds__hlds_llds.
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:- import_module hlds__instmap.
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:- import_module libs__globals.
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:- import_module libs__options.
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:- import_module libs__trace_params.
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:- import_module ll_backend__arg_info.
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:- import_module ll_backend__follow_vars.
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:- import_module ll_backend__liveness.
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:- import_module ll_backend__llds.
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:- import_module ll_backend__trace.
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:- import_module parse_tree__prog_data.
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:- import_module bool, int, require.
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:- import_module list, map, set, std_util, assoc_list.
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%-----------------------------------------------------------------------------%
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allocate_store_maps(RunType, ProcInfo0, PredId, ModuleInfo, ProcInfo) :-
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module_info_globals(ModuleInfo, Globals),
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( RunType = final_allocation ->
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proc_info_goal(ProcInfo0, Goal0),
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find_final_follow_vars(ProcInfo0,
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FollowVarsMap0, NextNonReserved0),
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proc_info_vartypes(ProcInfo0, VarTypes),
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find_follow_vars_in_goal(Goal0, VarTypes, ModuleInfo,
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FollowVarsMap0, NextNonReserved0,
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Goal1, FollowVarsMap, NextNonReserved),
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Goal1 = GoalExpr1 - GoalInfo1,
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FollowVars = follow_vars(FollowVarsMap, NextNonReserved),
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goal_info_set_follow_vars(GoalInfo1, yes(FollowVars),
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GoalInfo2),
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Goal2 = GoalExpr1 - GoalInfo2
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;
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proc_info_goal(ProcInfo0, Goal2)
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),
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initial_liveness(ProcInfo0, PredId, ModuleInfo, Liveness0),
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globals__get_trace_level(Globals, TraceLevel),
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module_info_pred_info(ModuleInfo, PredId, PredInfo),
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( eff_trace_level_is_none(PredInfo, ProcInfo0, TraceLevel) = no ->
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trace__fail_vars(ModuleInfo, ProcInfo0, ResumeVars0)
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;
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set__init(ResumeVars0)
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),
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arg_info__build_input_arg_list(ProcInfo0, InputArgLvals),
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LastLocns0 = initial_last_locns(InputArgLvals),
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proc_info_stack_slots(ProcInfo0, StackSlots),
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StoreAllocInfo = store_alloc_info(ModuleInfo, StackSlots),
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store_alloc_in_goal(Goal2, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, _, _),
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proc_info_set_goal(ProcInfo0, Goal, ProcInfo).
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:- func initial_last_locns(assoc_list(prog_var, lval)) = last_locns.
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initial_last_locns([]) = map__init.
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initial_last_locns([Var - Lval | VarLvals]) =
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map__det_insert(initial_last_locns(VarLvals), Var,
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set__make_singleton_set(Lval)).
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%-----------------------------------------------------------------------------%
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:- type store_alloc_info
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---> store_alloc_info(
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module_info :: module_info,
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stack_slots :: stack_slots
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% maps each var to its stack
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% slot (if it has one)
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).
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:- type where_stored == set(lval). % These lvals may contain var() rvals.
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:- type last_locns == map(prog_var, where_stored).
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:- pred store_alloc_in_goal(hlds_goal::in, liveness_info::in, set(prog_var)::in,
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last_locns::in, store_alloc_info::in, hlds_goal::out,
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liveness_info::out, last_locns::out) is det.
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store_alloc_in_goal(Goal0 - GoalInfo0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal - GoalInfo, Liveness, LastLocns) :-
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% note: we must be careful to apply deaths before births
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goal_info_get_pre_deaths(GoalInfo0, PreDeaths),
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goal_info_get_pre_births(GoalInfo0, PreBirths),
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goal_info_get_post_deaths(GoalInfo0, PostDeaths),
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goal_info_get_post_births(GoalInfo0, PostBirths),
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set__difference(Liveness0, PreDeaths, Liveness1),
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set__union(Liveness1, PreBirths, Liveness2),
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store_alloc_in_goal_2(Goal0, Liveness2, ResumeVars0, LastLocns0,
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PostDeaths, StoreAllocInfo, Goal, Liveness3, LastLocns),
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set__difference(Liveness3, PostDeaths, Liveness4),
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% If any variables magically become live in the PostBirths,
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% then they have to mundanely become live in a parallel goal,
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% so we don't need to allocate anything for them here.
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%
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% Any variables that become magically live at the end of the goal
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% should not be included in the store map.
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set__union(Liveness4, PostBirths, Liveness),
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( goal_util__goal_is_branched(Goal) ->
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set__union(Liveness4, ResumeVars0, MappedSet),
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set__to_sorted_list(MappedSet, MappedVars),
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( goal_info_maybe_get_store_map(GoalInfo0, StoreMapPrime) ->
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AdvisoryStoreMap = StoreMapPrime
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;
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AdvisoryStoreMap = map__init
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),
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store_alloc_allocate_storage(MappedVars, AdvisoryStoreMap,
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StoreAllocInfo, StoreMap),
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goal_info_set_store_map(GoalInfo0, StoreMap, GoalInfo)
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;
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GoalInfo = GoalInfo0
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).
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%-----------------------------------------------------------------------------%
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% Here we process each of the different sorts of goals.
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:- pred store_alloc_in_goal_2(hlds_goal_expr::in, liveness_info::in,
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set(prog_var)::in, last_locns::in, set(prog_var)::in,
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store_alloc_info::in, hlds_goal_expr::out, liveness_info::out,
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last_locns::out) is det.
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store_alloc_in_goal_2(conj(Goals0), Liveness0, ResumeVars0, LastLocns0,
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_, StoreAllocInfo, conj(Goals), Liveness, LastLocns) :-
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store_alloc_in_conj(Goals0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goals, Liveness, LastLocns).
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store_alloc_in_goal_2(par_conj(Goals0), Liveness0, ResumeVars0, LastLocns0,
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_, StoreAllocInfo, par_conj(Goals), Liveness, LastLocns) :-
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store_alloc_in_par_conj(Goals0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goals, Liveness, LastLocns).
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store_alloc_in_goal_2(disj(Goals0), Liveness0, ResumeVars0, LastLocns0,
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_, StoreAllocInfo, disj(Goals), Liveness, LastLocns) :-
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store_alloc_in_disj(Goals0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goals, Liveness, LastLocnsList),
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merge_last_locations(LastLocnsList, LastLocns).
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store_alloc_in_goal_2(not(Goal0), Liveness0, _ResumeVars0, LastLocns0,
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_, StoreAllocInfo, not(Goal), Liveness, LastLocns0) :-
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Goal0 = _ - GoalInfo0,
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goal_info_get_resume_point(GoalInfo0, ResumeNot),
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goal_info_resume_vars_and_loc(ResumeNot, ResumeNotVars, _),
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store_alloc_in_goal(Goal0, Liveness0, ResumeNotVars, LastLocns0,
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StoreAllocInfo, Goal, Liveness, _).
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store_alloc_in_goal_2(switch(Var, Det, Cases0), Liveness0, ResumeVars0,
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LastLocns0, _, StoreAllocInfo,
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switch(Var, Det, Cases), Liveness, LastLocns) :-
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store_alloc_in_cases(Cases0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Cases, Liveness, LastLocnsList),
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merge_last_locations(LastLocnsList, LastLocns).
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store_alloc_in_goal_2(if_then_else(Vars, Cond0, Then0, Else0),
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Liveness0, ResumeVars0, LastLocns0, _, StoreAllocInfo,
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if_then_else(Vars, Cond, Then, Else), Liveness, LastLocns) :-
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Cond0 = _ - CondGoalInfo0,
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goal_info_get_resume_point(CondGoalInfo0, ResumeCond),
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goal_info_resume_vars_and_loc(ResumeCond, ResumeCondVars, _),
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store_alloc_in_goal(Cond0, Liveness0, ResumeCondVars, LastLocns0,
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StoreAllocInfo, Cond, Liveness1, LastLocnsCond),
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store_alloc_in_goal(Then0, Liveness1, ResumeVars0, LastLocnsCond,
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StoreAllocInfo, Then, Liveness, LastLocnsThen),
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store_alloc_in_goal(Else0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Else, _Liveness2, LastLocnsElse),
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merge_last_locations([LastLocnsThen, LastLocnsElse], LastLocns).
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store_alloc_in_goal_2(some(Vars, CanRemove, Goal0), Liveness0, ResumeVars0,
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LastLocns0, _, StoreAllocInfo,
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some(Vars, CanRemove, Goal), Liveness, LastLocns) :-
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store_alloc_in_goal(Goal0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, Liveness, LastLocns).
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store_alloc_in_goal_2(generic_call(A, B, C, D), Liveness, _, LastLocns,
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_, _, generic_call(A, B, C, D), Liveness, LastLocns).
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store_alloc_in_goal_2(call(A, B, C, D, E, F), Liveness, _, LastLocns,
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_, _, call(A, B, C, D, E, F), Liveness, LastLocns).
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store_alloc_in_goal_2(unify(A,B,C,D,E), Liveness, _, LastLocns,
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_, _, unify(A,B,C,D,E), Liveness, LastLocns).
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store_alloc_in_goal_2(foreign_proc(A, B, C, D, E, F, G), Liveness, _,
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LastLocns, _, _, foreign_proc(A, B, C, D, E, F, G),
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Liveness, LastLocns).
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store_alloc_in_goal_2(shorthand(_), _, _, _, _, _, _, _, _) :-
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% these should have been expanded out by now
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error("store_alloc_in_goal_2: unexpected shorthand").
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%-----------------------------------------------------------------------------%
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:- pred store_alloc_in_conj(list(hlds_goal)::in, liveness_info::in,
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set(prog_var)::in, last_locns::in, store_alloc_info::in,
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list(hlds_goal)::out, liveness_info::out, last_locns::out) is det.
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store_alloc_in_conj([], Liveness, _, LastLocns, _, [], Liveness, LastLocns).
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store_alloc_in_conj([Goal0 | Goals0], Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, [Goal | Goals], Liveness, LastLocns) :-
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(
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% XXX should be threading the instmap
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Goal0 = _ - GoalInfo,
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goal_info_get_instmap_delta(GoalInfo, InstMapDelta),
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instmap_delta_is_unreachable(InstMapDelta)
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->
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store_alloc_in_goal(Goal0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, Liveness, LastLocns),
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Goals = Goals0
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;
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store_alloc_in_goal(Goal0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, Liveness1, LastLocns1),
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store_alloc_in_conj(Goals0, Liveness1, ResumeVars0, LastLocns1,
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StoreAllocInfo, Goals, Liveness, LastLocns)
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).
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%-----------------------------------------------------------------------------%
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:- pred store_alloc_in_par_conj(list(hlds_goal)::in, liveness_info::in,
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set(prog_var)::in, last_locns::in, store_alloc_info::in,
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list(hlds_goal)::out, liveness_info::out, last_locns::out) is det.
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store_alloc_in_par_conj([], Liveness, _, LastLocns, _,
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[], Liveness, LastLocns).
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store_alloc_in_par_conj([Goal0 | Goals0], Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, [Goal | Goals], Liveness, LastLocns) :-
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% XXX ignoring _Liveness1 looks fishy
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store_alloc_in_goal(Goal0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, Liveness, LastLocns1),
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store_alloc_in_par_conj(Goals0, Liveness0, ResumeVars0, LastLocns1,
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StoreAllocInfo, Goals, _Liveness1, LastLocns).
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%-----------------------------------------------------------------------------%
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:- pred store_alloc_in_disj(list(hlds_goal)::in, liveness_info::in,
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set(prog_var)::in, last_locns::in, store_alloc_info::in,
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list(hlds_goal)::out, liveness_info::out, list(last_locns)::out)
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is det.
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store_alloc_in_disj([], Liveness, _, _, _, [], Liveness, []).
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store_alloc_in_disj([Goal0 | Goals0], Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, [Goal | Goals], Liveness,
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[LastLocnsGoal | LastLocnsDisj]) :-
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Goal0 = _ - GoalInfo0,
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goal_info_get_resume_point(GoalInfo0, ResumeGoal),
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(
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ResumeGoal = no_resume_point,
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ResumeGoalVars = ResumeVars0
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;
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ResumeGoal = resume_point(ResumeGoalVars, _)
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),
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store_alloc_in_goal(Goal0, Liveness0, ResumeGoalVars, LastLocns0,
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StoreAllocInfo, Goal, Liveness, LastLocnsGoal),
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store_alloc_in_disj(Goals0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goals, _Liveness1, LastLocnsDisj).
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%-----------------------------------------------------------------------------%
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:- pred store_alloc_in_cases(list(case)::in, liveness_info::in,
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set(prog_var)::in, last_locns::in, store_alloc_info::in,
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list(case)::out, liveness_info::out, list(last_locns)::out) is det.
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store_alloc_in_cases([], Liveness, _, _, _, [], Liveness, []).
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store_alloc_in_cases([case(Cons, Goal0) | Goals0], Liveness0, ResumeVars0,
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LastLocns0, StoreAllocInfo, [case(Cons, Goal) | Goals],
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Liveness, [LastLocnsGoal | LastLocnsCases]) :-
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store_alloc_in_goal(Goal0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goal, Liveness, LastLocnsGoal),
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store_alloc_in_cases(Goals0, Liveness0, ResumeVars0, LastLocns0,
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StoreAllocInfo, Goals, _Liveness1, LastLocnsCases).
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%-----------------------------------------------------------------------------%
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%-----------------------------------------------------------------------------%
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:- pred merge_last_locations(list(last_locns)::in, last_locns::out) is det.
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merge_last_locations(LastLocnsList, LastLocns) :-
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( LastLocnsList = [LastLocnsPrime | _] ->
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LastLocns = LastLocnsPrime
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;
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LastLocns = map__init
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).
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%-----------------------------------------------------------------------------%
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%-----------------------------------------------------------------------------%
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% Given a follow_map which
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%
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% 1 may contain entries for non-live variables,
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%
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% 2 may contain no entry for a live variable,
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%
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% 3 which may map two live variables to one lval, and/or
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%
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% 4 map an lval to the artificial location reg(r(-1)),
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%
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% generate a store map that maps every live variable to its own
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% real location.
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:- pred store_alloc_allocate_storage(list(prog_var)::in, store_map::in,
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store_alloc_info::in, store_map::out) is det.
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store_alloc_allocate_storage(LiveVars, FollowVars, StoreAllocInfo, StoreMap) :-
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% This addresses point 1
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map__keys(FollowVars, FollowKeys),
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store_alloc_remove_nonlive(FollowKeys, LiveVars, FollowVars, StoreMap0),
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% This addresses points 3 and 4
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map__keys(StoreMap0, StoreVars),
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set__init(SeenLvals0),
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store_alloc_handle_conflicts_and_nonreal(StoreVars, 1, N,
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SeenLvals0, SeenLvals, StoreMap0, StoreMap1),
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% This addresses point 2
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store_alloc_allocate_extras(LiveVars, N, SeenLvals, StoreAllocInfo,
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StoreMap1, StoreMap).
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:- pred store_alloc_remove_nonlive(list(prog_var), list(prog_var),
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store_map, store_map).
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:- mode store_alloc_remove_nonlive(in, in, in, out) is det.
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store_alloc_remove_nonlive([], _LiveVars, StoreMap, StoreMap).
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store_alloc_remove_nonlive([Var | Vars], LiveVars, StoreMap0, StoreMap) :-
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( list__member(Var, LiveVars) ->
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StoreMap1 = StoreMap0
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;
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map__delete(StoreMap0, Var, StoreMap1)
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),
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store_alloc_remove_nonlive(Vars, LiveVars, StoreMap1, StoreMap).
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:- pred store_alloc_handle_conflicts_and_nonreal(list(prog_var),
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int, int, set(lval), set(lval), store_map, store_map).
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:- mode store_alloc_handle_conflicts_and_nonreal(in, in, out, in, out, in, out)
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is det.
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store_alloc_handle_conflicts_and_nonreal([], N, N, SeenLvals, SeenLvals,
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StoreMap, StoreMap).
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store_alloc_handle_conflicts_and_nonreal([Var | Vars], N0, N,
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SeenLvals0, SeenLvals, StoreMap0, StoreMap) :-
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map__lookup(StoreMap0, Var, Lval),
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(
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( artificial_lval(Lval)
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; set__member(Lval, SeenLvals0)
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)
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->
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next_free_reg(N0, SeenLvals0, N1),
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FinalLval = reg(r, N1),
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map__det_update(StoreMap0, Var, FinalLval, StoreMap1)
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;
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N1 = N0,
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FinalLval = Lval,
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StoreMap1 = StoreMap0
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),
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set__insert(SeenLvals0, FinalLval, SeenLvals1),
|
|
store_alloc_handle_conflicts_and_nonreal(Vars, N1, N,
|
|
SeenLvals1, SeenLvals, StoreMap1, StoreMap).
|
|
|
|
:- pred store_alloc_allocate_extras(list(prog_var), int, set(lval),
|
|
store_alloc_info, store_map, store_map).
|
|
:- mode store_alloc_allocate_extras(in, in, in, in, in, out) is det.
|
|
|
|
store_alloc_allocate_extras([], _, _, _, StoreMap, StoreMap).
|
|
store_alloc_allocate_extras([Var | Vars], N0, SeenLvals0, StoreAllocInfo,
|
|
StoreMap0, StoreMap) :-
|
|
(
|
|
map__contains(StoreMap0, Var)
|
|
->
|
|
% We have already allocated a slot for this variable.
|
|
N1 = N0,
|
|
StoreMap1 = StoreMap0,
|
|
SeenLvals1 = SeenLvals0
|
|
;
|
|
% We have not yet allocated a slot for this variable,
|
|
% which means it is not in the follow vars (if any).
|
|
StoreAllocInfo = store_alloc_info(_, StackSlots),
|
|
(
|
|
map__search(StackSlots, Var, StackSlot),
|
|
\+ set__member(StackSlot, SeenLvals0)
|
|
% Follow_vars was run, so the only
|
|
% reason why a var would not be in the
|
|
% follow_vars set is if it was supposed to
|
|
% be in its stack slot.
|
|
->
|
|
Locn = StackSlot,
|
|
N1 = N0
|
|
;
|
|
next_free_reg(N0, SeenLvals0, N1),
|
|
Locn = reg(r, N1)
|
|
),
|
|
map__det_insert(StoreMap0, Var, Locn, StoreMap1),
|
|
set__insert(SeenLvals0, Locn, SeenLvals1)
|
|
),
|
|
store_alloc_allocate_extras(Vars, N1, SeenLvals1, StoreAllocInfo,
|
|
StoreMap1, StoreMap).
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
% The follow_vars pass maps some variables r(-1) as a hint to the
|
|
% code generator to put them in any free register. Since store maps
|
|
% require real locations, we can't use such hints directly.
|
|
|
|
% For robustness, we check for N < 1 instead of N = -1.
|
|
|
|
:- pred artificial_lval(lval).
|
|
:- mode artificial_lval(in) is semidet.
|
|
|
|
artificial_lval(reg(_Type, Num)) :-
|
|
Num < 1.
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
:- pred next_free_reg(int, set(lval), int).
|
|
:- mode next_free_reg(in, in, out) is det.
|
|
|
|
next_free_reg(N0, Values, N) :-
|
|
( set__member(reg(r, N0), Values) ->
|
|
N1 = N0 + 1,
|
|
next_free_reg(N1, Values, N)
|
|
;
|
|
N = N0
|
|
).
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
%-----------------------------------------------------------------------------%
|